If the whistle varied with the WAD delay, I'd expect it was picking up the WAD's internal clock, but if it remains fixed, it is probably an op-amp on the res eq itself oscillating. Really, you are wasting your money on expensive op-amps. The circuits were not designed with them in mind, and any "improvement" they may make would be so small you would not notice it unless you were using test gear.
On Fri, Feb 3, 2017 at 5:33 PM, Stephen Richards okayjustalittle@... [cgs_synth] <cgs_synth@yahoogroups.com> wrote:Thanks Ken.The use of those was through the build thread on Muffs about three years ago. Jason suggested using those or OPA2134. So i decided then to try it. The RES EQ is mounted below the WAD. I'm going to test it without the WAD above it and see if the sound improves.From: "Ken Stone otherunicorn@... [cgs_synth]" <cgs_synth@yahoogroups.com>
To: cgs_synth@yahoogroups.com
Sent: Friday, February 3, 2017 1:57 PM
Subject: Re: [cgs_synth] CGS 202 Resonant Equalizer - high pitched noise on output.
use the correct op-amps.On Fri, Feb 3, 2017 at 10:11 AM, Stephen Richards okayjustalittle@... [cgs_synth] <cgs_synth@yahoogroups.com> wrote:I built the CGS 202 to incorporate into my new custom panel.Since testing i had noticed a constant very high pitched (around 12K) noise in the background of the output , even though the normal function of the Res Eq seems fine.I have used OP275 op amps in this build and styrenes for every single frequency. Wima caps everywhere else except the 47pF, which are ceramic.
--
--